"Diane’s incredible work on 'Hidden America' and her masterful interviews with Gabby Giffords, Malala Yousafzai and recently Hillary Clinton bring great distinction to the entire news division. Her curiosity, passion and energy inspire us all. Diane is one of the giants of modern journalism, and we can’t wait to see where she’ll lead us next," said ABC News President James Goldston.

David Muir will become the anchor and managing editor of "World News" starting Sept. 2, ABC said.

In addition, George Stephanopoulos will take on the new role as chief anchor of ABC News.

"George will be our lead anchor for major special events and breaking news at ABC, driving our live network coverage for the biggest stories," Goldston said. "From the retirement of Pope Benedict to the manhunt for the Boston bomber, George skillfully navigates uncertain and unfolding situations while synthesizing the latest reporting for our viewers. George is adept at balancing both complex global and public policy questions and deeply personal stories in interviews with numerous luminaries from Vladimir Putin to Angelina Jolie."

Over the last few weeks, ABC celebrated some terrific milestones -- No. 1 in the May sweep across the board and earning the highest honors for journalistic excellence in the Edward R. Murrow awards, Goldston said.